Geothermal Earth Loops for Rochester

January 13, 2012

In part three of our Introduction to Geothermal series, we are going to discuss geothermal loop systems and how each type works.

A geothermal loop is the series of underground pipes used to move heat to and from the earth. The pipes are formed out of high-density polyethylene to establish a dependable, long-lasting system. They are adhered together using thermal fusion that will develop a bond that is far stronger than the original pipe itself. In fact, a properly installed loop can remain up to 200 years.

There are two leading types of geothermal loop systems that are mostly used in today's installs: open loop systems and closed loop systems. Both systems have different pros and cons for your heating or cooling solution. We at Earth Energy Heating & Cooling Inc. have the knowledge and experience on both types, and we will guide you step by step in the process of selecting the best option for your geothermal installation.

Open loop geothermal solutions are designed to utilize the natural groundwater from below your home. Using a well, water is pulled from an existing aquifer and relocated to the geothermal heat pump where its heat is withdrawn and the water is pushed back into the ground or to a designated runoff. Since the water that you are using is not being treated in any way, the only thing that is being returned to the ground is water that is slightly warmer or cooler (depending whether you're in heating or cooling mode).

One thing to keep an eye on with an open loop system is water quality. Mineral build-up can happen from poor quality water. This can be kept under control with an occasional cleaning. If the water in the earth has greater iron content, you may want to make sure that the used water is prevented from coming in contact with air before it is returned to prevent clogs.

Closed loops are just as they sound. Rather than pumping water from a well and depositing it elsewhere, water is circulated in a completely sealed circuit with a small amount of environmentally-friendly antifreeze.

There are two primary types of closed loop installations: horizontal and vertical. Putting in the system horizontally needs quite a bit of land space. The piping is embedded in trenches between 4 and 6 feet deep and can be up to 400 feet long. If you reside on a smaller lot, the loops can be installed vertically by boring straight down using drilling equipment. This kind of installation can be installed in as little as a 10ft by 10ft area.

In either case, the larger the building, the larger the geothermal heat pump and loop needs to be. A good ball park figure is that for every ton of system capacity, you will need 500 to 600 feet of pipe.